It is known in the art to use cameras having charge-coupled device ("CCD") arrays to test the operation of liquid crystal displays ("LCDs") such as may be found on many cellular telephones. As information is fed from the telephone to be displayed on the LCD, testing generally requires that the LCD actually displays the information in the way designed. A technique to enable such testing is to view the LCD with a CCD camera as the information is sent to the LCD. The signal from the camera can be compared with the information sent to the LCD to verify accuracy to a high degree of resolution.
It will be understood that it is important for the CCD array in the camera to be able to be accurately aligned with the LCD array to enable precise testing. If the scan lines on the camera can be lined up accurately with the pixels on the LCD, the testing software generally works much more predictably. Camera mountings in the art generally allow fine adjustment of the camera's field of view by "sweeping" or "panning" along both X and Y directions in the plane of the arrays, but do not allow fine adjustment of rotation about a Z-axis orthogonal to the plane of the arrays and parallel to the optical axis of the camera. Hereinafter, such rotational adjustment about the Z-axis shall also be referred to "Theta" adjustment, or adjustment in the "Theta axis".
Prior art mounting devices are known to use translational stages to adjust position in X and Y directions. These stages consume significant space. Such prior art mounts also offer no Theta axis adjustment as a built-in feature, so that X, Y and Theta adjustment can be accomplished independently in a single device.
In addition to being large, prior art mounts tend to be very expensive. The large size and prohibitive expense of prior art mounts can be explained to some extent in that such mounts are almost universally designed for optical applications. There is a need in the art for a camera mount addressing the problems of digital testing in a confined space. In particular, it is sometimes desirable to place two or more CCD cameras in close proximity to test LCDs. The extravagant use of physical space by prior art mounts makes such multi-camera deployments very challenging.
Prior art mounts typically also lack locking mechanisms for holding the camera in place during and after adjustment and alignment. It is often desirable to move the entire testing assembly without upsetting the alignment.
There is therefore a need in the art for a camera mount independently adjustable in X, Y and Theta axes. A solution also providing compactness and cost economy will also provide measurable advantage, especially if multi-camera deployments are also enabled. A locking mechanism will provide further advantage towards preventing loss of alignment.